A leading farm sustainability expert has hit out at the portrayal of livestock farming as being bad for the environment, pointing out that it has an important role in building carbon stocks in the soil.
Taking part in an online Sheep Breeders Round Table event, Devenish Nutrition agriculture director Dr John Gilliland said it was “highly unfair” that policy makers focus on gross emissions from agriculture, while failing to take into account the carbon sequestered in soils.
“Our industry is being pulled through the gutters by the press. We are the custodians of the nation’s carbon – they need to look after us, not beat the living daylights out of us,” said Gilliland.
Currently leading an ARC Zero (Accelerating Ruminant Carbon to Zero) project which is calculating net emissions on seven farms across NI, Gilliland used the example of Roger and Hilary Bell, an 80ha beef and sheep farm outside Kells in Co Antrim. Comprehensive soil analysis done this past summer has identified that the soil on the farm currently holds nearly 14,000t of carbon.
If you plough, you will lose carbon
Across all seven ARC Zero farms, fields continually grazed by livestock tend to have more carbon than those cut for silage, while long-term work at AFBI Hillsborough has shown that soils receiving cattle slurry continue to store more carbon each year.
“If you plough, you will lose carbon. One of the things that really irritates me in the public debate at the moment, is the loss of soil carbon when growing human edible plant-based food is not properly recognised,” said Gilliland.
He pointed out that AFBI research suggests that if grassland is reseeded once every five years by ploughing, the soil can cope quite well and carbon stocks quickly recover in a matter of months.
On my own farm, we reckon we lost half our soil carbon in 30 years of tilling
“But if you are an arable farmer and you are cultivating every single year the soil has no chance to recover and you quietly lose your soil carbon. On my own farm, we reckon we lost half our soil carbon in 30 years of tilling,” he added.
On the Bell farm, initial analysis suggests that it has total carbon emissions of 820t annually, but the soil takes in 456t, leaving a net figure closer to 365t. If those figures were replicated across all farms it would dramatically change the narrative around the contribution agriculture makes to climate change.
However, Gilliland believes that there is significant potential to capture a lot more carbon in soils across Ireland, and points out that a healthy soil is one that is rich in carbon.
The first step is to correct soil pH in mineral soils as this improves soil biology, and its ability to take in carbon.
He also sees a place for multispecies swards (MSS), with initial results from both the Devenish research farm at Dowth in the Republic of Ireland, and on ARC Zero farms, suggesting that these swards are sequestering more carbon than conventional ryegrass.
It really depends on where government takes us
The third measure is to integrate more trees into grazing systems by the use of agroforestry.
While Gilliland accepts that it is a concept yet to gain much traction among farmers, he highlights that the soils with the highest carbon in the ARC Zero project are under woodland.
“It really depends on where government takes us. If they start paying us for carbon we might approach what we do in a different way,” he said.
For farmers across NI, the starting point for a new approach will be to participate in the recently announced soil nutrient health to be rolled out over the next five years.
One of the main outputs from the scheme will be to establish a carbon baseline for farms in NI.
Learning as we go with MSS
A second multi-species sward (MSS) that included plantain, chicory, red and white clover and two ryegrass varieties, was established on Roger and Hilary Bell’s farm outside Kells in Co. Antrim this year.
It will be interesting to see if it is going to last as well
According to Roger, the first field was one of the driest on the farm, and the MSS has continued to perform well. However, the second sward has been grown on one of the wettest fields. The Bell farm runs to 850ft above sea level, so it is potentially a good test of whether MSS can perform in more difficult conditions.
“It will be interesting to see if it is going to last as well [in the wetter field]. Probably persistency is going to be a challenge, but we are learning as we go,” Roger told last Thursday’s sheep breeders round table conference.
The advice from John Gilliland to anyone thinking of growing a MSS next year is to introduce it gradually onto the farm, and allocate a specific group of cattle or sheep to rotationally graze the new sward.